Patrons have tried for decades to sue for damages when they were frightened. But courts have consistently said that's the purpose of a haunted house.

It is the oldest warning in the book — parents tell their children not to talk to strangers. But one day a year we make an exception. And then some — even allowing our kids to ask those they don’t know for a Kit Kat. Parents definitely change the rules on Halloween.

Can the same be said for the legal system? Does it also tolerate otherwise unacceptable behavior simply because it takes place in the season of ghosts and goblins? By one measure, the answer is yes.

All sorts of legal duties are imposed on businesses to ensure that their visitors are free of danger. This seems simple enough. Unless you run a haunted house designed to frighten your guests. Those shelling out cash to tour such an attraction would be disappointed if steps were taken to remove all perils. But what if the fright goes further than planned and leads to an injury? Is the haunted house operator liable when the injured goes from "boo" to sue?

On a number of occasions, appeals courts have been required to answer this question. And despite rules designed to hold businesses liable when visitors leave in worse shape than when they entered, courts have consistently pointed to the unique nature of haunted houses to prevent those injured from recovering.

In 1996, in Mays v. Gretna Athletic Boosters, Inc., a Louisiana appeals court had before it a 10-year-old girl who was frightened when a character at a haunted house jumped out at her. She ran — directly into a cinder block wall covered with plastic sheeting. The court rejected the plaintiff's argument that covering a brick wall with black Visqueen, in a dark haunted house, is an unreasonably dangerous condition.

“The very nature of a Halloween haunted house is to frighten its patrons,” the court observed. "In order to get the proper effect, haunted houses are dark and contain scary and/or shocking exhibits. Patrons in a Halloween haunted house are expected to be surprised, startled and scared by the exhibits, but the operator does not have a duty to guard against patrons reacting in bizarre, frightened and unpredictable ways. Operators are duty-bound to protect patrons only from unreasonably dangerous conditions, not from every conceivable danger.”

It is not just the young who visit haunted houses. Bonanno v. Continental Casualty Co. involved an 84-year-old woman who fell while in the “devil’s den,” where a person disguised as the devil was mechanically projected into the room on an overhead track. The Louisiana appeals court, in 1973, declared that the visitor assumed the risk of being frightened, jostled and pushed about when she entered the attraction. As the court saw it, it did not matter whether Mary Bonanno fell as a result of being jostled by the crowd or in a frightened attempt to get away.

“She obviously had knowledge that she could anticipate being confronted by exhibits designed to startle and instill fear. She had to realize that the very nature of the attraction was to cause patrons to react in bizarre, frightened and unpredictable ways.” It would be inconsistent, the court decided, “to allow plaintiff to recover for damages which resulted from her being frightened, precisely the effect that the ‘Haunted House’ was calculated to produce.”

The timing of the injury is also not a reason to allow for recovery. In 1997, in Galan v. Covenant House New Orleans, the appeals court addressed an injury to a haunted house patron that occurred after her visit was thought to be over. After exiting and being thanked for coming, a woman was injured when “Jason” (the Friday the 13th character), who was hiding behind a Visqueen-covered fence, started up a chainsaw for purposes of frightening the visitors one last time.

The court was not convinced by the timing argument: “It appears to be plaintiff’s contention that this last exhibit, because it was unexpected, created an unreasonable risk of harm. ... The fact that the plaintiff did not expect this last exhibit does not mandate that the exhibit is unreasonable.” Apparently, haunted house visitors need to be on their toes until they get back into their car.

Perhaps the California appeals court summed it up best recently in Griffin v. The Haunted Hotel: “Being chased within the physical confines of The Haunted Trail by a chainsaw-carrying maniac is a fundamental part and inherent risk of this amusement. (The injured person) voluntarily paid money to experience it."

It has long been said that Americans can sue for anything. At least when it comes to a haunted house, that does not include getting what you paid for. The legal system is sometimes criticized for awarding money to the seemingly undeserving. But for those injured by the fright of a haunted house, the system is not that scary.

Randy Maniloff is a lawyer at White and Williams, LLP in Philadelphia.